The invention relates to a catalyst for hydroisomerization of sulfur and nitrogen contaminated hydrocarbon feedstocks, as well as a method for preparing the catalyst and a hydroisomerization process using the catalyst.
A persistent problem in the field of hydrocarbon processing and refining is the treatment of hydrocarbon feedstocks which are contaminated with sulfur and nitrogen. Sulfur and nitrogen contaminants tend to rapidly deactivate process catalysts and, furthermore, are undesirable fractions in the final product.
Numerous disclosures have been made proposing solutions to the sulfur and nitrogen contamination problem. Known processes include multi-stage treatments, severe limitations on the upper level of sulfur and nitrogen contaminants in the feedstock, and limited ability to remove sulfur and nitrogen from the process product. There thus still remains the need for a catalyst system for treatment, especially by hydroisomerization, of sulfur and nitrogen contaminated feedstock.
Further, hydroisomerization catalysts typically include one or more catalytically active metals which result in additional cost. It is therefore desirable to provide a catalyst system which is effective with reduced amounts of active metals.
It is therefore the primary object of the present invention to provide a catalyst system for hydroisomerization of a sulfur and nitrogen contaminated feedstock which is not rapidly poisoned by the contaminants in the feedstock.
It is a further object of the present invention to provide a catalyst system for treating a sulfur and nitrogen contaminated feedstock which serves to reduce the level of sulfur and nitrogen in the feedstock.
It is a still further object of the present invention to provide a catalyst system effective in treating a wide variety of hydrocarbon feedstocks using a reduced amount of catalytically active metal(s) so as to provide increased fractions of isomers in the final product.
It is another object of the present invention to provide a method for preparing a catalyst system according to the present invention.
It is still another object of the present invention to provide a hydroisomerization process using the catalyst system of the present invention for treating sulfur and nitrogen contaminated feedstocks.
Other objects and advantages of the present invention will appear hereinbelow.